Vintage HiFi Audio Forum

Repair / Help Forum => Repair / Help => Topic started by: strlok on November 08, 2020, 10:58:12 PM

Title: Adcom 5800 bias and DC balance repair help in Pittsburgh area?
Post by: strlok on November 08, 2020, 10:58:12 PM: Hey folks,

Found this forum from a google search trying to find vintage audio equipment repair in the Pittsburgh PA area.

I received a mint condition Adcom 5800 amp that I believe the bias and DC balance are off. The high end sounds harsh.

Supposedly the four cheap potentiometers, two for each channel, may have changed their position while enroute to me via shipment and need readjusted.

I was wondering if anyone here knows anyone in the Pittsburgh area that could help re-bias and adjust the DC balance in my Adcom? It also seems like swapping out the capacitors (this is an old 1994 amp) might be also beneficial but not sure.

Thanks,
Rob
Title: Re: Adcom 5800 bias and DC balance repair help in Pittsburgh area?
Post by: Sir Thrift-a-Lot on November 08, 2020, 11:07:33 PM: What part of town are you in? Do you have a manual?
Title: Re: Adcom 5800 bias and DC balance repair help in Pittsburgh area?
Post by: strlok on November 09, 2020, 01:47:19 AM: Hi, I live in the Castle Shannon area, South Hills.

I do have the 5800 Service Manual which has the schematics:

https://www.manualslib.com/manual/972393/Adcom-Gfa-5800.html#manual (https://www.manualslib.com/manual/972393/Adcom-Gfa-5800.html#manual)
Title: Re: Adcom 5800 bias and DC balance repair help in Pittsburgh area?
Post by: strlok on November 09, 2020, 01:49:36 AM: Sorry doesn't look like I can edit my previous post.

But here is an owner's manual as well:

https://www.manualslib.com/manual/206141/Adcom-Gfa-5800.html (https://www.manualslib.com/manual/206141/Adcom-Gfa-5800.html)
Title: Re: Adcom 5800 bias and DC balance repair help in Pittsburgh area?
Post by: Vpgh on November 09, 2020, 09:48:12 PM: Quote from: strlok on November 09, 2020, 01:49:36 AM
Sorry doesn't look like I can edit my previous post.

But here is an owner's manual as well:

https://www.manualslib.com/manual/206141/Adcom-Gfa-5800.html (https://www.manualslib.com/manual/206141/Adcom-Gfa-5800.html)
You can call to Galaxie Electronics @ Murray/Sq. Hills.
Title: Re: Adcom 5800 bias and DC balance repair help in Pittsburgh area?
Post by: strlok on November 09, 2020, 09:57:42 PM: Quote from: vpgh on November 09, 2020, 09:48:12 PM
You can call to Galaxie Electronics @ Murray/Sq. Hills.

Thanks for the recommendation. Can you tell me more about Galaxie Electronics? Are they experts at repairing old Adcoms?
Title: Re: Adcom 5800 bias and DC balance repair help in Pittsburgh area?
Post by: strlok on November 09, 2020, 10:54:36 PM: Ooof I'm dumb. Looking through your post history looks like you run Galaxie. 8)

Sorry about that. I will give you a call ASAP (looks like Thursday is when you open back up shop at 10am).

Thank you for responding.
Title: Re: Adcom 5800 bias and DC balance repair help in Pittsburgh area?
Post by: Sir Thrift-a-Lot on November 09, 2020, 11:58:49 PM: Quote from: strlok on November 09, 2020, 10:54:36 PM
Ooof I'm dumb. Looking through your post history looks like you run Galaxie. 8)

You're not as dumb as me. I didn't realize that.
Title: Re: Adcom 5800 bias and DC balance repair help in Pittsburgh area?
Post by: MacGeek on November 10, 2020, 08:06:09 AM: I am not sure about Adcom, but Galaxy is good at vintage hi-fi, IMO. My experience suggests they are fair and stand behind their work. I last talked to Vince a couple of months ago and hours of operation have been restricted, due to COVID. I suggest talking to them before taking your gear for service.

By the way, Vince told me he does not like working on surface soldered circuitry or subwoofers.
Title: Re: Adcom 5800 bias and DC balance repair help in Pittsburgh area?
Post by: scorpio333 on November 10, 2020, 09:35:00 AM: Quote from: strlok on November 09, 2020, 10:54:36 PM
Ooof I'm dumb. Looking through your post history looks like you run Galaxie. 8)

Sorry about that. I will give you a call ASAP (looks like Thursday is when you open back up shop at 10am).

Thank you for responding.

I'm fairly certain vpgh and Vince from Galaxie are NOT related in any way...or did I miss something???

Vince from Galaxie is more old school, he doesn't like the newer integrated chip "black face crap". Regardless, shoot him a call and be patient, last I heard he was knee deep with no end in sight.
Title: Re: Adcom 5800 bias and DC balance repair help in Pittsburgh area?
Post by: strlok on November 10, 2020, 09:11:08 PM: Quote from: scorpio333 on November 10, 2020, 09:35:00 AM
I'm fairly certain vpgh and Vince from Galaxie are NOT related in any way...or did I miss something???

I looked through his post history and his name is Vince, so I assumed they are the same person?

Quote
he doesn't like the newer integrated chip "black face crap".
Do you have an example of what you mean by this? Sorry I'm sorta new to audio electronics in general and wonder what you mean.

Thanks again guys for your help!
Title: Re: Adcom 5800 bias and DC balance repair help in Pittsburgh area?
Post by: EmperorNorton on November 11, 2020, 07:02:59 PM: I will chime in here.

There are absolutely two Vinces. One is the moderator here and the other runs Galaxie Electronics.
"black faced crap" is a somewhat pejorative term used to describe the styling of much consumer grade audio gear manufactured in the 80s and beyond.
It was the design syle that replaced the classic 60'/70's silver faced/ wood cabinets of the Pioneer/ Yamaha/Marantz equipment, to give a few examples.

Welcome aboard, by the way!!

The Emp
Title: Re: Adcom 5800 bias and DC balance repair help in Pittsburgh area?
Post by: Vpgh on November 11, 2020, 10:56:26 PM: Quote from: EmperorNorton on November 11, 2020, 07:02:59 PM
I will chime in here.

There are absolutely two Vinces. One is the moderator here and the other runs Galaxie Electronics.
"black faced crap" is a somewhat pejorative term used to describe the styling of much consumer grade audio gear manufactured in the 80s and beyond.
It was the design syle that replaced the classic 60'/70's silver faced/ wood cabinets of the Pioneer/ Yamaha/Marantz equipment, to give a few examples.

Welcome aboard, by the way!!

The Emp
Thank you, Emperor!
Title: Re: Adcom 5800 bias and DC balance repair help in Pittsburgh area?
Post by: Sir Thrift-a-Lot on November 12, 2020, 12:24:14 AM: Quote from: scorpio333 on November 10, 2020, 09:35:00 AM
integrated chip "black face crap".

I've always heard it as black plastic crap or simply BPC.
Title: Re: Adcom 5800 bias and DC balance repair help in Pittsburgh area?
Post by: scorpio333 on November 12, 2020, 08:36:04 AM: Quote from: Sir Thrift-a-Lot on November 12, 2020, 12:24:14 AM
Quote from: scorpio333 on November 10, 2020, 09:35:00 AM
integrated chip "black face crap".

I've always heard it as black plastic crap or simply BPC.

I believe you are correct...black face is a whole different realm we don't need to talk about.
Title: Re: Adcom 5800 bias and DC balance repair help in Pittsburgh area?
Post by: strlok on November 12, 2020, 10:41:43 AM: Ok I got in touch with Vince at Galaxie and he referred me over to Kevin at Progressive Electronics. Any experiences with his work?
Title: Re: Adcom 5800 bias and DC balance repair help in Pittsburgh area?
Post by: geoffr on November 12, 2020, 12:04:51 PM: I
Title: Re: Adcom 5800 bias and DC balance repair help in Pittsburgh area?
Post by: MacGeek on November 13, 2020, 08:43:46 AM: I have used Kevin's services on a number of occasions. He is the McIntosh authorized service center and may be for other brands as well. Kevin is not cheap, but uses quality parts and stands behind his work. He actually lives in Ohio and comes to Pittsburgh on Wednesdays. The local shop is next to the Eat n Park in Dormont.

Kevin was the service tech at the Listening post when they were around. He is the only one anywhere near here who knows how to service B & O. He is selective and will not work on everything, so I suggest calling him about your unit before dropping it off. Also, turnaround time is typically six or more weeks, regardless of his good intentions to get it done sooner.

Progressive Audio: 412-571-2202 You may need to call him more than once.
Title: Re: Adcom 5800 bias and DC balance repair help in Pittsburgh area?
Post by: EmperorNorton on November 13, 2020, 05:38:10 PM: Kevin repaired a Yamaha pre-amp and I was very happy with his work
Title: Re: Adcom 5800 bias and DC balance repair help in Pittsburgh area?
Post by: strlok on November 17, 2020, 07:36:54 PM: Quote from: MacGeek on November 13, 2020, 08:43:46 AM
He is the only one anywhere near here who knows how to service B & O.

Wow that's pretty cool considering there's only a few B&O certified techs left in USA.

I contacted Kevin and will be dropping this unit off tomorrow.

Thanks guys for the useful info and help.
Title: Re: Adcom 5800 bias and DC balance repair help in Pittsburgh area?
Post by: MacGeek on November 18, 2020, 08:26:39 AM: I don't know if he is a certified tech, but he knows how to service B & O
Title: Re: Adcom 5800 bias and DC balance repair help in Pittsburgh area?
Post by: andersKH on January 28, 2021, 09:15:29 PM: Glad you found someone to look at it. I don't do repairs much anymore and mostly do my own stuff.
I do recommend Vince but he is very busy. We need new young people interested in doing repairs.
I might be willing to help a new person.